Fat utilisation in threshold interval session (not asking F/U at threshold)

[Twowkg]

Fat vs. Carbohydrate Utilization At Different Power Zones

This question has been studied extensively since the mid/late 1800s (no, not a typo). You will therefore be able to find graphs of the relationship between estimated fat and carbohydrate oxidation and exercise intensity in practically any undergraduate exercise physiology textbook and all over the web. Generally speaking, however, in the fasted state (i.e., no recent food intake) we use mostly fat at rest, with a bit of a jump up to closer to a 50/50 mixture during low intensity exercise. From …